Electrosurgical instruments such as, for example, the APC probes used in endoscopy, frequently comprise a gas conduit through which gas is supplied, and a power supply line that conducts HF electrical current. As a rule, the probes are connected to an electrical appliance that controls the supplies of gas and current, by means of connecting leads.
The patent EP 0447121 A2 discloses a probe connected to such an appliance by connecting devices such that the gas and HF current conducted to the probe in separate connecting devices are not brought together until they are in the vicinity of the front tip of the probe. Therefore, especially when the probe is used in gastroenterology, secretions and fluids from human or animal bodies can enter the gas and power supply lines during treatment and contaminate them. This contamination occurs not only in the parts of the lines that are inside the probe but also in those parts connected to the probe. As a consequence, after such contamination has occurred, both the probe and also the connecting lines must be replaced.
Although the connecting devices disclosed in EP 0447121 A2 for connecting the probe to the leads that come from the appliance incorporate a filter, which is intended to provide protection against such contamination, this filter is positioned in such a way that only the appliance is protected.
Accordingly, it is the object of the present invention to provide a connecting device for an electrosurgical instruments that makes it possible efficaciously to protect the connecting leads associated with the instrument, or integrated therein, against contamination by secretions and fluids from human or animal bodies.